Rapper mechanical arrangement of a radiant syngas cooler

ABSTRACT

An embodiment in accordance with the present invention provides a device and method for removing ash from an interior surface of a radiant synthesis gas cooler. The device for removing ash includes a rapper actuator, a striker pin coupled to the rapper actuator including a proximal end and a distal end, and a striker target assembly disposed such that a proximal surface of the striker target assembly is in contact with the distal end of the striker pin and a distal surface is in contact with the surface of the radiant synthesis gas cooler.

FIELD AND BACKGROUND OF THE INVENTION

The present invention relates generally to the field of coalgasification and, to a Radiant Synthesis Gas (syngas) Cooler (RSC) foran Integrated Gasification Combined Cycle (IGCC) power plant. Moreparticularly, the present invention relates to a rapper to remove ashfrom pressure parts within the RSGC.

The Radiant Synthesis Gas Cooler (RSC) is a component of an IntegratedGasification Combined Cycle (IGCC) power plant. Hot gas and molten ashfrom the gasification process enter the top of a vertical pressurevessel. Inside the vertical pressure vessel are pressure parts that coolthe gas and generate steam for the steam turbine cycle. Ash attaches tothe pressure parts in a process called ash deposition. Ash depositionreduces the heat transfer through the pressure parts and steam flow tothe turbine. Therefore, in order to maintain power output for the plantit is desirable for at least some of the ash to be removed from thepressure parts.

One such method for removing the ash from the pressure parts is to usesootblowers that use nitrogen as a cleaning fluid. However, many ofthese sootblowers have been removed from service and their effectivenessto clean is not known. Accordingly, it is desirable to provide a methodand apparatus to remove the ash from the pressure parts of the RSC.

SUMMARY OF THE INVENTION

The foregoing needs are met, to a great extent, by the presentinvention, wherein in one aspect a device is provided that in someembodiments removes ash from an interior surface of a radiant synthesisgas cooler in order to increase steam flow and therefore power output ina power plant.

In accordance with one aspect of the present invention, a device forremoving ash from a surface of a radiant synthesis gas cooler includes arapper actuator, a striker pin coupled to the rapper actuator includinga proximal end and a distal end, and a striker target assembly disposedsuch that a proximal surface of the striker target assembly is incontact with the distal end of the striker pin and a distal surface isin contact with the surface of the radiant synthesis gas cooler. Thestriker target assembly can also include a striker target plate. Thestriker target plate can include a cylindrical bar or can include twostriker target plates.

In accordance with another aspect of the present invention, the strikertarget assembly includes a wear plate mounted on the interior surface ofthe radiant synthesis gas cooler such that the wear plate is in contactwith the distal end of the striker target plate. Additionally, therapper actuator can take the form of a pneumatic rapper actuator or anelectromagnetic actuator. The striker target assembly can be movablydisposed within the radiant synthesis gas cooler.

In accordance with another aspect of the present invention, a strikertarget assembly for removing ash from an interior surface of a radiantsynthesis gas cooler includes a tube cage assembly defining a slot, astriker target plate including a distal surface and a proximal surface,wherein the striker target plate extends through the slot, and a wearplate mounted on the interior surface of the radiant synthesis gascooler such that the wear plate is in contact with the distal surface ofthe striker target plate. The striker target assembly can be movablydisposed within the radiant synthesis gas cooler, and the striker targetassembly can also include a striker pin in contact with the proximalsurface of the striker target assembly.

In accordance with yet another aspect of the present invention thestriker target plate, the striker pin, and the wear plate are all inalignment. Also, the striker target plate can include two striker targetplates. Additionally, the tube cage assembly can include a membranesurrounding an outside surface of the tube cage assembly and themembrane defines an opening through which the striker target plateextends. Further, there can be a gap between the striker target plateand the membrane.

In accordance with still another aspect of the present invention, amethod of removing ash from a radiant synthesis gas cooler includesmounting a wear plate on an interior surface of the radiant synthesisgas cooler from which the ash is to be removed and contacting a surfaceof the wear plate with a distal surface of a striker target plate thatextends through a tube cage assembly of the radiant synthesis gascooler. The method can also include contacting a proximal surface of thestriker target plate with a striker pin and inducing a vibration in theinterior surface, from which the ash is to be removed, by transmitting arapping energy through the striker pin to the striker target plate andthe wear plate.

In accordance with another aspect of the present invention, the methodfurther includes aligning the wear plate, the striker target plate, andthe striker pin. The method can also include producing a rapping energyusing a rapper actuator and mounting the striker target plate movablywithin the radiant synthesis gas cooler. Additionally, the method caninclude a striker target plate including two striker target plates.

There has thus been outlined, rather broadly, certain embodiments of theinvention in order that the detailed description thereof herein may bebetter understood, and in order that the present contribution to the artmay be better appreciated. There are, of course, additional embodimentsof the invention that will be described below and which will form thesubject matter of the claims appended hereto.

In this respect, before explaining at least one embodiment of theinvention in detail, it is to be understood that the invention is notlimited in its application to the details of construction and to thearrangements of the components set forth in the following description orillustrated in the drawings. The invention is capable of embodiments inaddition to those described and of being practiced and carried out invarious ways. Also, it is to be understood that the phraseology andterminology employed herein, as well as the abstract, are for thepurpose of description and should not be regarded as limiting.

As such, those skilled in the art will appreciate that the conceptionupon which this disclosure is based may readily be utilized as a basisfor the designing of other structures, methods and systems for carryingout the several purposes of the present invention. It is important,therefore, that the claims be regarded as including such equivalentconstructions insofar as they do not depart from the spirit and scope ofthe present invention.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a perspective view illustrating a rapper in accordance with anembodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The invention will now be described with reference to the drawingfigures, in which like reference numerals refer to like partsthroughout. An embodiment in accordance with the present inventionprovides an apparatus for removing ash from pressure parts of a RadiantSynthesis Gas Cooler (RSC). The embodiments in accordance with thepresent invention may include a rapper actuator, a striker pin, astriker target, and wear plates.

FIG. 1 is a perspective view illustrating a rapper mechanicalarrangement 10, according to one embodiment of the invention. Thecomponents are a rapper actuator 12, a striker pin 14, and a strikertarget assembly 16. The rapper actuator 12 can be pneumatic orelectromagnetic. The striker pin 14 is spring loaded to assure that thestriker pin 14 is in constant contact with the striker target assembly16. The striker target assembly 16 is a composite assembly of partsdescribed herein.

The rapper actuator 12 attaches to a flange 18 that is mounted on anoutside surface of a wall 20 of a pressure vessel 22. The pressurevessel 22 is operated at pressures above atmospheric pressure and theenvironment inside the pressure vessel is in general corrosive. Thereare seals and inert gas purge to allow the penetration of the strikerpin 14 through the pressure vessel wall 20 and without leakage of syngasto the atmosphere. Inside the pressure vessel is a tube and membraneconstruction pressure part assembly, sometimes called a tube cageassembly 24 that is typically round, but can be multiple sided. The tubecage assembly 24 is completely seal welded to contain the syngas. Thereis a space between the pressure vessel wall 20 and the tube cageassembly 24 called an annulus 26. The annulus 26 is continually purgedwith an inert gas to assure syngas does not remain in the annulus 26 andcause corrosion of tubes 28 forming the tube cage assembly 24 or thewall 20 of the pressure vessel 22.

On the inside of the tube cage assembly 24 are other pressure partassemblies 30 that absorb heat to produce steam. The pressure partassemblies 30 are sometimes called platens, division walls or wingwalls. These internal pressure part assemblies 30 have ash depositing onthe surface that reduce heat transfer and steam production. To maintainthe required or expected steam production, the internal pressure partassemblies 30 need to be cleaned. Rapping energy induces a vibration inthe pressure part assemblies 30 that induces shedding of the ashdeposits. The highest rapping energy is transmitted to the internalpressure part assemblies 30 when there is direct contact between therapper actuator 12 and the internal pressure part assemblies 30 and whenthe striker pin 14 and striker target assembly 16 are free to move.

One embodiment involves the striker target assembly 16, which includesat least one striker target plate 32. If two striker target plates 32are used, they are located on opposite sides of a tube. There are slots34 in the tube cage assembly 24 so that the striker target plate 32 canpass from the annulus 26 to the internal pressure part assemblies 30.The slots 34 are created by leaving a portion of a membrane 40surrounding the tube cage assembly 24 off the assembly. The strikertarget plate 32 is sized to provide small gaps around the plateperiphery, which minimize the amount of inert purge gas leakage from theannulus and allows for free movement of the target. The close fitbetween the striker target plate 32 and the tube cage assembly 24maintains alignment between the striker pin 14 and the striker targetassembly 16.

The internal pressure part assembly 30, the tube cage assembly 24, andthe pressure vessel 22 operate at different temperatures. The thermalexpansion of each component is different. Additionally, the internalpressure part assembly 30 can bow due to differential expansions. Theinternal pressure part assembly 30 must be oriented inline with thestriker pin 14 and the striker target assembly 16. The striker targetassembly 16 must also be in alignment with the internal pressure partassembly 30. The alignment is provided with tubes 36 from the pressurepart assembly 30 which are bent around the striker target assembly 16.Attached to the tubes 36 are wear plates 38 that protect the tubes 36and provide the alignment of the striker target assembly 16 and theinternal pressure part assembly 30.

Alignment of the striker target assembly 16 to the internal pressureparts assembly 30 is provided while allowing free movement between theinternal pressure part assembly 30, tube cage assembly 24, and thestriker target assembly 16. Additionally, free movement of the strikertarget assembly 16 within the tube cage assembly 24 is provided, whichmaximizes the transmitted energy to the internal pressure part assembly30. The gap between the annulus 26 and an internal side of the tube cageassembly 24 is minimized, which, in turn, minimizes the amount of inertgas leakage.

The many features and advantages of the invention are apparent from thedetailed specification, and thus, it is intended by the appended claimsto cover all such features and advantages of the invention which fallwithin the true spirit and scope of the invention. Further, sincenumerous modifications and variations will readily occur to thoseskilled in the art, it is not desired to limit the invention to theexact construction and operation illustrated and described, andaccordingly, all suitable modifications and equivalents may be resortedto, falling within the scope of the invention.

1. A device for removing ash from a surface of a radiant synthesis gascooler comprising: a rapper actuator; a striker pin coupled to therapper actuator including a proximal end and a distal end; and a strikertarget assembly disposed such that a proximal surface of the strikertarget assembly is in contact with the distal end of the striker pin anda distal surface is in contact with the surface of the radiant synthesisgas cooler.
 2. The device of claim 1, wherein the striker targetassembly comprises a striker target plate.
 3. The device of claim 2,wherein the striker target plate comprises a cylindrical bar.
 4. Thedevice of claim 2, wherein the striker target plate comprises twostriker target plates.
 5. The device of claim 2, wherein the strikertarget assembly comprises a wear plate mounted on the interior surfaceof the radiant synthesis gas cooler such that the wear plate is incontact with the distal end of the striker target plate.
 6. The deviceof claim 1, wherein the device comprises a pneumatic rapper actuator. 7.The device of claim 1, wherein the device comprises an electromagneticactuator.
 8. The device of claim 1, wherein the striker target assemblyis movably disposed within the radiant synthesis gas cooler.
 9. Astriker target assembly for removing ash from an interior surface of aradiant synthesis gas cooler comprising: a tube cage assembly defining aslot; a striker target plate including a distal surface and a proximalsurface, wherein the striker target plate extends through the slot; anda wear plate mounted on the interior surface of the radiant synthesisgas cooler such that the wear plate is in contact with the distalsurface of the striker target plate.
 10. The striker target assembly ofclaim 9, wherein the striker target assembly is movably disposed withinthe radiant synthesis gas cooler.
 11. The striker target assembly ofclaim 9, further comprising a striker pin in contact with the proximalsurface of the striker target assembly.
 12. The striker target assemblyof claim 11, wherein the striker target plate, the striker pin, and thewear plate are all in alignment.
 13. The striker target assembly ofclaim 9, wherein the striker target plate comprises two striker targetplates.
 14. The striker target assembly of claim 9, wherein the tubecage assembly comprises a membrane surrounding an outside surface of thetube cage assembly and the membrane defines an opening through which thestriker target plate extends.
 15. The striker target assembly of claim14, further comprising a gap between the striker target plate and themembrane.
 16. A method of removing ash from a radiant synthesis gascooler comprising: mounting a wear plate on an interior surface of theradiant synthesis gas cooler from which the ash is to be removed;contacting a surface of the wear plate with a distal surface of astriker target plate that extends through a tube cage assembly of theradiant synthesis gas cooler; contacting a proximal surface of thestriker target plate with a striker pin; and inducing a vibration in theinterior surface, from which the ash is to be removed, by transmitting arapping energy through the striker pin to the striker target plate andthe wear plate.
 17. The method of claim 16, further comprising aligningthe wear plate, the striker target plate, and the striker pin.
 18. Themethod of claim 16, further comprising producing a rapping energy usinga rapper actuator.
 19. The method of claim 16, further comprisingmounting the striker target plate movably within the radiant synthesisgas cooler.
 20. The method of claim 16, further comprising a strikertarget plate comprising two striker target plates.